Portfolio Team field has limited access from JQL within JIRA

JPO-66 had introduced mapping the "team" field to JIRA. This is fantastic. However, JQL only allows "=" and "in" operators. They also don't accept EMPTY or NULL.

Also, getting this value in any scripting plug-in such as issue.get(“Team”) returns com.atlassian.jpo.team.data.DefaultTeam. This latter class is not exposed yet in the JIRA API.

The request is to be able to query this field for the scrum board filter for any issues that don't have a team assigned. i.e. "project = XYZ and Team = EMPTY". Alternatively, if the NULL/EMPTY value can't be returned, this could be written as "project = XYZ and Team not in (TeamA, TeamB, TeamC)".

Can this enhancement be considered or please indicate if there is a current workaround.

Thanks

NOTE: The JQL using Portfolio Team field doesn't return subtasks in the results - JPOCLOUD-1805